It estimates that some 13,000 cluster munitions were fired, containing nearly two million sub-munitions, that could well have killed or wounded in excess of 1,000 people.

The bulk of these cluster-munitions were fired by US artillery systems and the report says that the US Army needs to learn a lesson that the Air Force has already adopted, namely that cluster munitions cannot be used in populated areas without huge loss of civilian life.

The report also condemns the policy of so-called precision attacks against Iraqi leadership targets.

In 50 such strikes it says no Iraqi leaders were killed but dozens of civilians were.

It points to significant intelligence failings.

"Its no good using a precise weapon " said the organisation's Executive Director Kenneth Roth, "if the target hasn't been located precisely".